Abstract: Thermal radiation can cause larger ablation pressure and mass ablation rate than laser-driven at the same intensity. A code of 1-D radiation hydrodynamics has been developed and the ablative radiation wave propagating in Au planar targets has been numerically investigated. The scaling laws was obtained for Au planar targets, such as the radiation flow, ablative pressure, mass ablation rate and characteristic plasma density in the case of a constant boundary temperature, are given in this paper.